Stevenson, MW, Warpeha, JM, Dietz, CC, Giveans, RM, and Erdman, AG. Acute effects of elastic bands during the free-weight barbell back squat exercise on velocity, power, and force production. J Strength Cond Res 24(11): 2944-2954, 2010-The use of elastic bands in resistance training has been reported to be effective in increasing performance-related parameters such as power, rate of force development (RFD), and velocity. The purpose of this study was to assess the following measures during the free-weight back squat exercise with and without elastic bands: peak and mean velocity in the eccentric and concentric phases (PV-E, PV-C, MV-E, MV-C), peak force (PF), peak power in the concentric phase, and RFD immediately before and after the zero-velocity point and in the concentric phase (RFDC). Twenty trained male volunteers (age = 26.0 ± 4.4 years) performed 3 sets of 3 repetitions of squats (at 55% one repetition maximum [1RM]) on 2 separate days: 1 day without bands and the other with bands in a randomized order. The added band force equaled 20% of the subjects' 55% 1RM. Two independent force platforms collected ground reaction force data, and a 9-camera motion capture system was used for displacement measurements. The results showed that PV-E and RFDC were significantly (p < 0.05) greater with the use of bands, whereas PV-C and MV-C were greater without bands. There were no differences in any other variables. These results indicate that there may be benefits to performing squats with elastic bands in terms of RFD. Practitioners concerned with improving RFD may want to consider incorporating this easily implemented training variation.